Internal and external reviews that fault NASA's management also endorse the strategy of many eggs in many baskets. (See story on page 1.) They do not want NASA to return to its old practice of loading most of its scientific exploration onto a few billion-dollar-plus missions. It took 10 to 20 years to get some of those into space.

It is sensible to divide at least some parts of a major program, such as Mars exploration, into smaller, cheaper missions that can be designed, built, and launched within a few years.

The National Academy of Sciences, for example, calls this strategy "generally sound." But it warns that "heavy emphasis on tight schedules and cost cutting is jeopardizing the scientific objectives." Smaller, cheaper missions, with fewer managers and less-stringent quality control, are inherently riskier.

NASA has said it is prepared to lose a few of these. The academy warns that such losses are hurting science. It notes, too, that some missions, such as returning Mars samples, need more elaborate spacecraft. It urges NASA to design missions according to the scientific objectives and not try to fit the science into a single faster, cheaper strategy. This means a mix of small, medium, and a few large missions.

NASA administrator Daniel Goldin admits that the agency has pushed "too fast" in "doing more with less." He says the agency now is reassessing its practices. This requires a major culture change for both NASA and its contractors. Corner cutting and inadequate management have created an atmosphere that discourages tight quality control.

To NASA's credit, it has had 136 successful launches and only 10 failures since 1992. That represents a loss of under 3 percent of total costs. Mr. Goldin calls this "world-class performance by any reasonable standard."

There's some justice in that claim. Nevertheless, critics are also justified in asking why the agency can't have the kind of high-quality program management that put astronauts on the moon three decades ago.